Study on the microstructure and adsorption mechanism of different silver-based iodine adsorbents

To further clarify the iodine adsorption mechanism of three-dimensional ordered macroporous silver-silica (3DOM-SA) composite aerogel, based on the establishment of the relationship between pore structure and adsorption properties, the kinetic analysis of the adsorption process of gaseous iodine was carried out, and a comprehensive comparison was made with silver nitrate impregnated silica (AgS) which has been applied in engineering. The results show that the adsorption of gaseous iodine by 3DOM-SA and AgS fits well with the pseudo-second-order and pseudo-first-order kinetic model, corresponding to the main roles played by chemical adsorption and physical adsorption. The iodine adsorption capacity of 3DOM-SA (925 ± 46 mg/g) is much larger than that of AgS (64 ± 11 mg/g) due to the 3DOM structure and more dispersed nano-active components.